1. Field of the Invention
The present invention relates to the use of selected 1,2-dihydro-1,2,4,5-tetrazines as oxygen-scavengers in liquid systems.
2. Description of the Prior Art
Dissolved oxygen in liquids such as water may cause extensive pitting and other forms of corrosion to metal surfaces coming in contact with these liquids. For example, this corrosion may cause serious problems to boiler systems and the like.
Accordingly, removal of oxygen from liquid streams and systems is highly desirable in many instances. Such deoxygenation can be carried out by either mechanical or chemical means or with both. In those situations where chemical deoxygenation is desired, various chemicals including sodium sulfite, hydrazine, and hydroquinone have been employed as chemical oxygen-scavengers. See U.S. Pat. Nos. 3,551,349 (Kallfass); 3,843,547 (Kaufman et al); 3,983,048 (Schiessl); 4,012,195 (Noack); 4,022,711 (Noack); 4,022,712 (Noack); 4,026,664 (Noack); 4,079,018 (Noack); 4,096,090 (Noack) and 4,269,717 (Slovinsky) as teaching of the use of hydrazine or similar compounds as oxygen-scavengers and corrosion inhibitors. See U.S. Pat. Nos. 4,278,635 (Kerst); 4,279,767 (Muccitelli); and 4,282,111 (Ciuba) as teaching of the use of hydroquinone and the like as an oxygen-scavengers. All of these cited U.S. Patents are incorporated herein by reference in their entireties.
While much work has been accomplished in this area, there is still a need to find more effective oxygen-scavengers for particular liquid systems. It is believed that the present invention presents a solution to this need.